PHARMACEUTICAL  GLEANINGS  AND  NOTICES.  323 
the  collodion  should  be  wiped  off  with  a  little  cotton  wool  moist- 
ened with  ether,  when  the  blister  will  almost  instantly  rise." 
In  comparing  the  collodion  of  Mr.  Tichborne  with  that  in 
common  use  in  the  United  States,  almost  the  only  difference  is 
in  the  presence  of  acetic  acid.  Now,  there  can  be  but  little 
doubt  that  the  acetic  acid  in  this  preparation  has  a  caustic  ac- 
tion of  its  own,  independent  of  the  cantharidin,  and  it  may  fa- 
cilitate the  action  of  the  cantharides ;  yet  as  to  the  necessity  of 
this  aid,  or  of  that  other  influence  it  exerts  on  the  consist- 
ence of  the  collodion,  there  is  abundant  reason  to  doubt,  unless 
it  be  required  to  effect  the  vesicoation  in  the  shortest  possible 
time.  From  Mr.  T.'s  statement  of  the  time  required,  we  believe 
his  vesicant  is  quicker  in  its  action  than  that  in  use  here,  but 
in  no  other  respect  does  it  appear  to  us  improved,  whilst  the 
cost  is  increased.  We  would  also  suggest  that  it  is  a  mistake 
to  use  the  cantharides  in  coarse  powder,  and  that  the  quantity 
of  menstruum  used  by  Mr.  T.  is  insufficient  to  thoroughly  ex- 
haust the  flies.  With  these  remarks  we  will  offer  the  recipe 
which  was  provisionally  adopted  by  the  revising  Committee  of 
the  U.  S.  Pharmacopoeia. 
Take  of  Cantharides,  in  fine  powder,  eight  ounces. 
Cotton,  prepared  as  for  collodion,  [gun  cotton]  100  grs. 
Ether,  a  sufficient  quantity. 
Pack  the  cantharides  firmly  in  a  percolator,  cover  it  with  mus- 
lin and  pour  on  ether  until  fourteen  fluid  ounces  have  slowly 
passed.  Dissolve  the  gun  cotton  in  this  liquid,  set  it  aside, 
and  continue  the  percolation  until  eight  fluidounces  more  of 
the  ethereal  liquid  is  displaced,  which  is  to  be  evaporated  till  it 
measures  two  fluidounces.  Lastly,  add  this  to  the  first  liquid  and 
mix  thoroughly.  If  after  standing  24  hours  a  sediment  should 
be  observed,  decant  the  clear  collodion,  which  should  possess  a 
decided  green  color,  and  preserve  it  in  a  close  bottle. 
Sinapic  Collodion. — Mr.  Tichborne  also  suggests  the  follow- 
ing recipe  for  applying  oil  of  Black  Mustard  as  a  rubefacient : 
Take  of  Volatile  Oil  of  Black  Mustard  a  fluidrachm. 
Collodion,  six  fluidrachms. 
Acetic  acid  (glacial)  gtt.  xx. 
The  acid  is  introduced  to  modify  the  consistence  of  the  collo- 
dion.   This  preparation  occasions  more  pain  than  that  with 
